cochraxe



UNiTED sra'ras ra'rnn'r orrica.

JNO. COC-HRANE, Ol NEY YORK, N. Y.

RAIL FOR RAILROADS.

Specification of Letters Patent No. 22,103, dated November 16, 1858.

To all whom 'it may concern:

Be it known that I, JOHN COCHRANE, of the city and county of New York and State of New York, have invented a new and useful Improvement in the Manufacture of IVrought-Iron Bars for Railroad-Tracks; and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings and to the letters of reference marked thereon.

The nature of my invention consists in consolidating the top portion and bearing surface of the rail by means of a secondary process of hammering or rolling; and in giving the crown of the rail such form, while passing through the rolls, in the first process, as will secure this result.

To enable others skilled in the art to make and use my invention I will proceed to describe the same.

The wrought iron rails in common use for rail-road tracks are fashioned into form and finished by being successively passed through the grooved rolls of a mill; a process which is well known and understood, and which answers the purpose sufficient-ly for all parts of the rail except the bearing surface of the head or crown; which part, from the nature of the operation, being merely lateral pressure, is less solid than the other parts of the same bar, although it ought to be the most solid and thoroughly worked part of the whole rail, because of the abrasive pressure to which itis subjected in use by the passage over it of heavy locomotive engines at high velocities. To obviate this well known defect in the rail, as produced by the ordinary method or process of rolling, various modes of manufacture and forms of rail have been devised so as to obtain rails which would have the top portion of the proper quality of iron, or be subject to the direct pressure of the rolls while passing through them. It would seem, however, from the test of practice, that most of these devices while they afford a remedy to some extent for some of the evils complained of, they possess other evils which are quite as objectionable.

The form of rail which is now almost universally adopted is that of an inverted T, as shown in the annexed drawing at A A, and consists of the three parts a al, which is the head, Z) b the vertical rib and c c the bottom flange; all of which are made in one and the same piece, and this is substantially the form of rail which I prefer, but I do not mean to confine myself, in any particular, to the sizes or proportions of the several parts here shown in the drawing.

In my improved mode of manufacture two different or several machines Iare required. The first of these is the ordinary double roll, but this machine cannot give the proper solidity or density to the head of the rail, as already explained. I therefore enlarge the central part of the crown of the rail, as shown at B in the drawing, by grooving the rolls to the proper form for that purpose, and the rails having successively passed through the several grooves of the rolls are finished in every respect, as in the usual way, except the top part or crown of the rail, upon which the additional metal has been left in order that it shall be forced into the head of the rail, by the second machine or process and thereby brought to the propel' degree of density and hardness which may be done in various ways; but the mode which I prefer is by hammering: a machine for which purpose I have invented and propose to make the subject of a separate patent. This second machine should be placed in proper range with the last part of the rolls through which the rail passes when it leaves the rolls, and at the distance of the full length of the rail, and to which machine the rail should be immediately introduced, while it is hot and in an incandescent state, by passing it between the side rolls C and D, which are molded to suit the rail up to the center of the beads of the head a a, while the flange c c should move along on the solid and level cast iron bed piece E, leaving the upper portion of the rail Open to the action of the hammer I?, the face of which is molded or shaped to the proper form of the bearing surface of the rail, down to the center of the edges or beads of the head a a. The rail on passing through the second machine or process is thoroughly consolidated and finished on the bearing surface or crown to the proper form.

In rail-road bars, which are made by the common mode of manufacture, the central part of the crown or bearing surface is considerably softer and less compact than the edges, and therefore less capable of resisting the effects of abrasion and heavy pressure; the consequence is the comparatively rapid wear of the central part of the rail throws an undue strain upon the edges, which being further aggravated by the crushing down and spreading of the central part of the head either splits off the edges or spreads them out into jagged splinters, often along their whole length. Another evil which arises from this condition of the iron in the head of the rail is the bruising down of the ends of the rails at the joints; the injurious effects of which upon the machinery are so well known that it has become a mattei' of special inquiry to devise some method by which this difficulty might be obviated. But in my improved manufacture a suliicient quantity of metal is left upon the crown of the rail by the first process to give it the necessary compactness and hardness when consolidated by the second process, thus producing a rail in which the central part of the bearing surface will have the greatest solidity, which is well known to be the true principle of formation, for if the central part of the bearing surface will not crush, the edges of the rail can neither split off nor eXfoliate; nor will the ends bruise down as in the common rail. I therefore claim thiat my improved method of manufacture will greatly increase the durability of the rails while the additional cost of the second process is so trifling as to be of no importance in comparison to its advantages, and

it may be more than counterbalfanced by the reduction in the weight of the material for a given degree of strength.

Having thus described my improvements in the manufacture of Wrought iron rails or bars for rail-road tracks, What I claim therein as my invention yand desire to secure by Letters Patent is- The making or forming of such rails, by means of rolls, with additional metal upon the crown or head thereof, which additional metal is forced into the head or top part of the rail by a second process, thereby consolidating the head or top part of the rail and hardening the bearing surface thereof, substantially as described.

JOHN COCHRANE.

fitnesses a JON. L. PEAKE, Jas. A. KENT. 

